Renal pyelectasis in pregnancy: correlative evaluation of fetal and maternal collecting systems.

Objective: The current study is aimed at assessing the possibility of a statistical relationship between fetal and maternal collecting system dilatation during pregnancy.

Study Design: Two hundred thirty consecutive pregnant women and their fetuses (20 to 40 weeks' gestation) were simultaneously examined by ultrasonography. The renal collecting systems were measured, and the frequency of dilatation was subjected to chi 2 analysis. The temporal incidence of fetal pyelectasis was compared with the maternal incidence.

Results: Dilatation of maternal collecting systems was detected in 91 of 230 patients (40%) and fetal pyelectasis occurred in 60 of 230 (26%). Fetal pyelectasis was 5.6 times more likely to occur in fetuses of mothers with dilated collecting systems. Furthermore, the temporal incidence of fetal pyelectasis throughout pregnancy appeared similar to that of maternal pyelectasis.

Conclusion: This study points out the existence of a statistically significant association between maternal and fetal collecting system dilatation during pregnancy.